Composite Soft Sensor for Sensitive Compressive Force Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing soft sensors, particularly capacitive dielectric elastomers, are insensitive to compressive forces due to their incompressibility, limiting their application in areas requiring sensitive force detection.
Innovation Solution
A sensor comprising a reversibly deformable composite layer made of an elastomer material with dispersed conductive filler, such as carbon black, configured to exhibit a negative change in permittivity upon force application, and interdigitated electrodes to detect changes in capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If voids or gaps are incorporated to assist deformation, then compressive force detection is enabled, but structural complexity increases
Solution Approach 1:
Instead of incorporating physical voids or gaps, the patent changes the electrical parameter (permittivity) of the solid composite material itself. The conductive filler creates a network that responds to compression through permittivity change, avoiding the need for complex void structures while achieving compressive force detection
Solution Approach 2:
The patent distributes conductive filler material locally throughout the elastomer matrix to create regions with specific electrical properties. This local modification of material quality enables compressive force detection without requiring global structural changes or void incorporation
2Measurement precision
If conductive filler material is added to elastomer, then negative permittivity change under compression is achieved, but electrical losses increase
Solution Approach 1:
The patent uses a marginal or optimal quantity of conductive filler material that is sufficient to create the negative permittivity change effect but not excessive enough to cause significant electrical losses. This partial action approach balances the competing requirements of achieving the desired electrical response while minimizing energy loss
3Measurement precision
If filler material quantity is increased to maximize permittivity change, then sensitivity improves, but mechanical stiffening occurs
Solution Approach 1:
The patent uses an optimal or marginal quantity of filler material that provides sufficient permittivity change for high sensitivity while avoiding excessive filler content that would cause mechanical stiffening. This partial action principle finds the sweet spot between electrical performance and mechanical compliance
Solution Approach 2:
The patent optimizes the concentration parameter of the conductive filler material to achieve the desired balance between electrical sensitivity and mechanical properties. By carefully controlling this parameter, the composite maintains the elasticity needed for soft sensor applications while exhibiting the negative permittivity change required for high sensitivity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The sensor provides high sensitivity and rapid response to compressive forces, enabling accurate force detection and safe interaction with humans or fragile objects, with minimal mechanical stiffening and electrical losses.
Implementation Method 1
the quantity of filler material in the elastomer material is configured to provide a negative change in permittivity of the composite layer upon the composite layer being subjected to a force
Implementation Method 2
detect changes in capacitance
Implementation Method 3
a composite layer, the composite layer being reversibly deformable
Data Source
AI summary
A soft sensor which may be used in robotic grasping applications includes a composite material being reversibly deformable and comprising an elastomer material containing dispersed conductive filler material, wherein the quantity of filler material in the elastomer material is configured to provide a negative change in permittivity of the composite layer upon the composite layer being subjected to a force.